GSF meaning in Regional ?

The Georgia Southern and Florida Railway (reporting mark GSF), also known as the Suwanee River Route from its crossing of the Suwanee River, was founded in 1885 as the Georgia Southern and Florida Railroad and began operations between Macon, GA and Valdosta, GA in 1889, extending to Palatka, FL in 1890. The railroad went bankrupt by 1891, was reorganized as the Georgia Southern and Florida Railway in 1895, and was controlled by the Southern Railway.

In 1902, the GS&F purchased the Atlantic, Valdosta and Western Railway that ran from Valdosta, GA to Jacksonville, FL. The GS&F also owned the Macon and Birmingham Railway and the Hawkinsville and Florida Southern Railway, both of which were operated as separate companies; both ended up going bankrupt and being mostly abandoned. The GS&F was eventually acquired by the Norfolk Southern Railway and still operates as a subsidiary. As of November 2012, at least one operating Norfolk Southern locomotive retains GSF reporting marks.